Tetrahydronaphthalene derivatives

ABSTRACT

This invention relates to novel tetrahydronaphthalene derivatives, and pharmaceutically acceptable salts thereof according to the following formulae, in one embodiment: 
     
       
         
         
             
             
         
       
     
     as described herein. 
     This invention also provides compositions comprising a compound of this invention and the use of such compositions in methods of treating diseases and conditions that are beneficially treated by administering a selective T-type calcium channel blocker.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S.Provisional Application No. 61/309,672, filed Mar. 2, 2010, and U.S.Provisional Application No. 61/351,500, filed Jun. 4, 2010, both ofwhich are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

Many current medicines suffer from poor absorption, distribution,metabolism and/or excretion (ADME) properties that prevent their wideruse or limit their use in certain indications. Poor ADME properties arealso a major reason for the failure of drug candidates in clinicaltrials. While formulation technologies and prodrug strategies can beemployed in some cases to improve certain ADME properties, theseapproaches often fail to address the underlying ADME problems that existfor many drugs and drug candidates. One such problem is rapid metabolismthat causes a number of drugs, which otherwise would be highly effectivein treating a disease, to be cleared too rapidly from the body. Apossible solution to rapid drug clearance is frequent or high dosing toattain a sufficiently high plasma level of drug. This, however,introduces a number of potential treatment problems such as poor patientcompliance with the dosing regimen, side effects that become more acutewith higher doses, and increased cost of treatment. A rapidlymetabolized drug may also expose patients to undesirable toxic orreactive metabolites.

Another ADME limitation that affects many medicines is the formation oftoxic or biologically reactive metabolites. As a result, some patientsreceiving the drug may experience toxicities, or the safe dosing of suchdrugs may be limited such that patients receive a suboptimal amount ofthe active agent. In certain cases, modifying dosing intervals orformulation approaches can help to reduce clinical adverse effects, butoften the formation of such undesirable metabolites is intrinsic to themetabolism of the compound.

In some select cases, a metabolic inhibitor will be co-administered witha drug that is cleared too rapidly. Such is the case with the proteaseinhibitor class of drugs that are used to treat HIV infection. The FDArecommends that these drugs be co-dosed with ritonavir, an inhibitor ofcytochrome P450 enzyme 3A4 (CYP3A4), the enzyme typically responsiblefor their metabolism (see Kempf, D. J. et al., Antimicrobial agents andchemotherapy, 1997, 41(3): 654-60). Ritonavir, however, causes adverseeffects and adds to the pill burden for HIV patients who must alreadytake a combination of different drugs. Similarly, the CYP2D6 inhibitorquinidine has been added to dextromethorphan for the purpose of reducingrapid CYP2D6 metabolism of dextromethorphan in a treatment ofpseudobulbar affect. Quinidine, however, has unwanted side effects thatgreatly limit its use in potential combination therapy (see Wang, L etal., Clinical Pharmacology and Therapeutics, 1994, 56(6 Pt 1): 659-67;and FDA label for quinidine at www.accessdata.fda.gov).

In general, combining drugs with cytochrome P450 inhibitors is not asatisfactory strategy for decreasing drug clearance. The inhibition of aCYP enzyme's activity can affect the metabolism and clearance of otherdrugs metabolized by that same enzyme. CYP inhibition can cause otherdrugs to accumulate in the body to toxic levels.

A potentially attractive strategy for improving a drug's metabolicproperties is deuterium modification. In this approach, one attempts toslow the CYP-mediated metabolism of a drug or to reduce the formation ofundesirable metabolites by replacing one or more hydrogen atoms withdeuterium atoms. Deuterium is a safe, stable, non-radioactive isotope ofhydrogen. Compared to hydrogen, deuterium forms stronger bonds withcarbon. In select cases, the increased bond strength imparted bydeuterium can positively impact the ADME properties of a drug, creatingthe potential for improved drug efficacy, safety, and/or tolerability.At the same time, because the size and shape of deuterium areessentially identical to those of hydrogen, replacement of hydrogen bydeuterium would not be expected to affect the biochemical potency andselectivity of the drug as compared to the original chemical entity thatcontains only hydrogen.

Over the past 35 years, the effects of deuterium substitution on therate of metabolism have been reported for a very small percentage ofapproved drugs (see, e.g., Blake, M I et al, J Pharm Sci, 1975,64:367-91; Foster, A B, Adv Drug Res 1985, 14:1-40 (“Foster”); Kushner,D J et al, Can J Physiol Pharmacol 1999, 79-88; Fisher, M B et al, CurrOpin Drug Discov Devel, 2006, 9:101-09 (“Fisher”)). The results havebeen variable and unpredictable. For some compounds deuteration causeddecreased metabolic clearance in vivo. For others, there was no changein metabolism. Still others demonstrated increased metabolic clearance.The variability in deuterium effects has also led experts to question ordismiss deuterium modification as a viable drug design strategy forinhibiting adverse metabolism (see Foster at p. 35 and Fisher at p.101).

The effects of deuterium modification on a drug's metabolic propertiesare not predictable even when deuterium atoms are incorporated at knownsites of metabolism. Only by actually preparing and testing a deuterateddrug can one determine if and how the rate of metabolism will differfrom that of its non-deuterated counterpart. See, for example, Fukuto etal. (J. Med. Chem. 1991, 34, 2871-76). Many drugs have multiple siteswhere metabolism is possible. The site(s) where deuterium substitutionis required and the extent of deuteration necessary to see an effect onmetabolism, if any, will be different for each drug.

This invention relates to novel tetrahydronaphthalene derivatives, andpharmaceutically acceptable salts thereof. This invention also providescompositions comprising a compound of this invention and the use of suchcompositions in methods of treating diseases and conditions that arebeneficially treated by administering a selective T-type calcium channelblocker.

Mibefradil also known as(1S,2S)-2-(2-((3-(2-benzimidazolylpropyl)methylamino)ethyl)-6-fluoro-1,2,3,4-tetrahydro-1-isopropyl-2-naphthylmethoxyacetate dihydrochloride is a calcium channel blocker that isknown to selectively and potently block the T-type calcium channel and,through a de-esterified metabolite, to also block the L-type calciumchannel (Massie, B. M., Am J Cardiol., 1997, Nov. 6, 80(9A):23I-32I).The pharmacologic activity of the de-esterified metabolite isapproximately 10% that of the parent(http://www.drugs.com/mmx/mibefradil-dihydrochloride.html).

Mibefradil has demonstrated strong blood pressure reducing effects inpatients with mild, moderate and severe hypertension, with lessperipheral edema effects than other calcium channel blockers(Lacourcière, Y. et al., Am J Hypertens. 1997 February; 10(2):189-96;)and has proven effective at improving exercise tolerance and reducingischemic episodes in patients with chronic stable angina (see Massieabove). Mibefradil was approved by the FDA in 1997 for treatment ofhypertension, angina and cardiac failure, then was voluntarily withdrawnin 1998 due to potent drug-drug interactions with other medicationsresulting largely from its strong CYP3A4/5 inhibition and potentiallyalso due to PGP inhibition (Wandel, C. et al., Drug Metabolism andDisposition, 2000, 28(8): 895-898). Although the exact mechanism ofCYP3A inhibition is not known, it has been suggested that it resultsfrom oxidation of the benzimidazole moiety of mibefradil (Fontan, E etal, Curr Drug Metab 2005, 6:413-43).

Mibefradil is known to undergo metabolism through two metabolicpathways: esterase-catalyzed hydrolysis of the ester side chain(producing an alcohol metabolite known as Ro 40-5966); and cytochromeP450 3A4-catalyzed oxidation. Plasma concentrations of the alcoholmetabolite resulting from de-esterification increase during chronicdosing and exceed those of the parent mibefradil at doses of 100 mg. Thepharmacologic effect of the metabolite is approximately 10% of that ofthe parent (http://www.drugs.com/mmx/mibefradil-dihydrochloride.html).Mibefradil's and Ro-40-5966's CYP 3A4 metabolism occurs predominantly attwo molecular sites, most prominently the benzylic site of thetetrahydronaphthalene, and also to a significant extent alpha to thetertiary amine leading to removal of the N-methyl or thepropylbenzimidazole groups. CYP 3A4 catalyzed metabolism also occurs toa limited extent on the benzimidazole ring of mibefradil at both the 4-and 5-positions (Wiltshire, H. R. et al., Xenobiotica, 1997, 27(6):539-556).

When administered intravenously to healthy male volunteers, mibefradilcaused a dose-dependent increase in bilirubin in all cases, and a severedecrease in plasma haptoglobin in two cases (Kleinbloesem C. H. et al.,Journal of Cardiovascular Pharmacology, 1995, 25(6): 855-858).

Despite the beneficial activities of mibefradil, there is a continuingneed for new compounds to treat the aforementioned diseases andconditions.

Definitions

The term “treat” means decrease, suppress, attenuate, diminish, arrest,or stabilize the development or progression of a disease (e.g., adisease or disorder delineated herein), lessen the severity of thedisease or improve the symptoms associated with the disease.

“Disease” means any condition or disorder that damages or interfereswith the normal function of a cell, tissue, or organ.

The term “carbocyclyl” refers to a monocyclic hydrocarbon ring systemsuch as cycloalkyl and phenyl.

The term “cycloalkyl” refers to a monocyclic monovalent saturated ornon-aromatic unsaturated hydrocarbon ring system. The term “C₃-C₆cycloalkyl” refers to a cycloalkyl wherein the number of ring carbonatoms is from 3 to 6. More particular examples of cycloalkyl groupsinclude, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cyclopropenyl, cyclobuten-2-yl, cyclobuten-3-yl, etc.

The term “carbocyclic ring” refers to a saturated or non-aromaticunsaturated ring. The term “3-6-membered carbocyclic ring” refers to acarbocyclic ring wherein the number of ring carbon atoms is from 3 to 6.A carbocyclic ring may be a ring having, for example, two freevalencies, which may be two free valencies at the same carbon, such asthe following rings:

It will be recognized that some variation of natural isotopic abundanceoccurs in a synthesized compound depending upon the origin of chemicalmaterials used in the synthesis. Thus, a preparation of mibefradil willinherently contain small amounts of deuterated isotopologues. Theconcentration of naturally abundant stable hydrogen and carbon isotopes,notwithstanding this variation, is small and immaterial as compared tothe degree of stable isotopic substitution of compounds of thisinvention. See, for instance, Wada, E et al., Seikagaku, 1994, 66:15;Gannes, L Z et al., Comp Biochem Physiol Mol Integr Physiol, 1998,119:725.

In the compounds of this invention any atom not specifically designatedas a particular isotope is meant to represent any stable isotope of thatatom. Unless otherwise stated, when a position is designatedspecifically as “H” or “hydrogen”, the position is understood to havehydrogen at its natural abundance isotopic composition. Also unlessotherwise stated, when a position is designated specifically as “D” or“deuterium”, the position is understood to have deuterium at anabundance that is at least 3340 times greater than the natural abundanceof deuterium, which is 0.015% (i.e., at least 50.1% incorporation ofdeuterium).

The term “isotopic enrichment factor” as used herein means the ratiobetween the isotopic abundance and the natural abundance of a specifiedisotope.

In other embodiments, a compound of this invention has an isotopicenrichment factor for each designated deuterium atom of at least 3500(52.5% deuterium incorporation at each designated deuterium atom), atleast 4000 (60% deuterium incorporation), at least 4500 (67.5% deuteriumincorporation), at least 5000 (75% deuterium), at least 5500 (82.5%deuterium incorporation), at least 6000 (90% deuterium incorporation),at least 6333.3 (95% deuterium incorporation), at least 6466.7 (97%deuterium incorporation), at least 6600 (99% deuterium incorporation),or at least 6633.3 (99.5% deuterium incorporation).

The term “isotopologue” refers to a species in which the chemicalstructure differs from a specific compound of this invention only in theisotopic composition thereof.

The term “compound,” when referring to a compound of this invention,refers to a collection of molecules having an identical chemicalstructure, except that there may be isotopic variation among theconstituent atoms of the molecules. Thus, it will be clear to those ofskill in the art that a compound represented by a particular chemicalstructure containing indicated deuterium atoms, will also contain lesseramounts of isotopologues having hydrogen atoms at one or more of thedesignated deuterium positions in that structure. The relative amount ofsuch isotopologues in a compound of this invention will depend upon anumber of factors including the isotopic purity of deuterated reagentsused to make the compound and the efficiency of incorporation ofdeuterium in the various synthesis steps used to prepare the compound.However, as set forth above the relative amount of such isotopologues intoto will be less than 49.9% of the compound. In other embodiments, therelative amount of such isotopologues in toto will be less than 47.5%,less than 40%, less than 32.5%, less than 25%, less than 17.5%, lessthan 10%, less than 5%, less than 3%, less than 1%, or less than 0.5% ofthe compound.

The invention also provides salts of the compounds of the invention.

A salt of a compound of this invention is formed between an acid and abasic group of the compound, such as an amino functional group, or abase and an acidic group of the compound, such as a carboxyl functionalgroup. According to another embodiment, the compound is apharmaceutically acceptable acid addition salt.

Throughout the application all references to “a compound of Formula A”or “a compound of Formula I” or “a compound of Formula B” or “a compoundof Formula B-I” or “a compound of the invention” or “a compound ofclaim” include, within the scope of each such term, syntheticallyfeasible pharmaceutically acceptable salts of such a compound.

The term “pharmaceutically acceptable,” as used herein, refers to acomponent that is, within the scope of sound medical judgment, suitablefor use in contact with the tissues of humans and other mammals withoutundue toxicity, irritation, allergic response and the like, and arecommensurate with a reasonable benefit/risk ratio. A “pharmaceuticallyacceptable salt” means any non-toxic salt that, upon administration to arecipient, is capable of providing, either directly or indirectly, acompound of this invention. A “pharmaceutically acceptable counterion”is an ionic portion of a salt that is not toxic when released from thesalt upon administration to a recipient.

Acids commonly employed to form pharmaceutically acceptable saltsinclude inorganic acids such as hydrogen bisulfide, hydrochloric acid,hydrobromic acid, hydroiodic acid, sulfuric acid and phosphoric acid, aswell as organic acids such as para-toluenesulfonic acid, salicylic acid,tartaric acid, bitartaric acid, ascorbic acid, maleic acid, besylicacid, fumaric acid, gluconic acid, glucuronic acid, formic acid,glutamic acid, methanesulfonic acid, ethanesulfonic acid,benzenesulfonic acid, lactic acid, oxalic acid, para-bromophenylsulfonicacid, carbonic acid, succinic acid, citric acid, benzoic acid and aceticacid, as well as related inorganic and organic acids. Suchpharmaceutically acceptable salts thus include sulfate, pyrosulfate,bisulfate, sulfite, bisulfite, phosphate, monohydrogenphosphate,dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide,iodide, acetate, propionate, decanoate, caprylate, acrylate, formate,isobutyrate, caprate, heptanoate, propiolate, oxalate, malonate,succinate, suberate, sebacate, fumarate, maleate, butyne-1,4-dioate,hexyne-1,6-dioate, benzoate, chlorobenzoate, methylbenzoate,dinitrobenzoate, hydroxybenzoate, methoxybenzoate, phthalate,terephthalate, sulfonate, xylene sulfonate, phenylacetate,phenylpropionate, phenylbutyrate, citrate, lactate, β-hydroxybutyrate,glycolate, maleate, tartrate, methanesulfonate, propanesulfonate,naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate and othersalts. In one embodiment, pharmaceutically acceptable acid additionsalts include those formed with mineral acids such as hydrochloric acidand hydrobromic acid, and especially those formed with organic acidssuch as maleic acid.

The compounds of the present invention (e.g., compounds of Formula B,B-I, A or Formula I), may contain an asymmetric carbon atom, forexample, as the result of deuterium substitution or otherwise. As such,compounds of this invention can exist as either individual enantiomers,or mixtures of the two enantiomers. Accordingly, a compound of thepresent invention may exist as either a racemic mixture or a scalemicmixture, or as individual respective stereoisomers that aresubstantially free from another possible stereoisomer. The term“substantially free of other stereoisomers” as used herein means lessthan 25% of other stereoisomers, preferably less than 10% of otherstereoisomers, more preferably less than 5% of other stereoisomers andmost preferably less than 2% of other stereoisomers are present. Methodsof obtaining or synthesizing an individual enantiomer for a givencompound are known in the art and may be applied as practicable to finalcompounds or to starting material or intermediates.

Unless otherwise indicated, when a disclosed compound is named ordepicted by a structure without specifying the stereochemistry and hasone or more chiral centers, it is understood to represent all possiblestereoisomers of the compound.

The term “stable compounds,” as used herein, refers to compounds whichpossess stability sufficient to allow for their manufacture and whichmaintain the integrity of the compound for a sufficient period of timeto be useful for the purposes detailed herein (e.g., formulation intotherapeutic products, intermediates for use in production of therapeuticcompounds, isolatable or storable intermediate compounds, treating adisease or condition responsive to therapeutic agents).

“D” and “d” both refer to deuterium. “Stereoisomer” refers to bothenantiomers and diastereomers. “Tert” and “t-” each refer to tertiary.“US” refers to the United States of America.

“Substituted with deuterium” refers to the replacement of one or morehydrogen atoms with a corresponding number of deuterium atoms.

Throughout this specification, a variable may be referred to generally(e.g.,“each R”) or may be referred to specifically (e.g., R¹, R², R³,etc.). Unless otherwise indicated, when a variable is referred togenerally, it is meant to include all specific embodiments of thatparticular variable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. CYP3A4 mechanism-based inhibition (MBI) in human livermicrosomes (HLM) of Deuterated Mibefradil, compound 500 and compound703a.

THERAPEUTIC COMPOUNDS

The present invention provides a compound of Formula B:

or a pharmaceutically acceptable salt thereof, wherein:

R^(a) and R^(b) are each independently selected from —CH₃, —CDH₂, —CD₂H,and —CD₃;

R^(d) and R^(e) are each independently hydrogen or deuterium; or R^(d)and R^(e) taken together with the carbon to which they are connectedform a 3-6-membered carbocyclic ring that is optionally substituted withdeuterium;

provided that if R^(d) and R^(e) are each independently hydrogen ordeuterium, then R^(f) is OR^(c) wherein R^(c) is selected from —CH₃,—CDH₂, —CD₂H, and —CD₃;

and provided that if R^(d) and R^(e) taken together with the carbon towhich they are connected form a 3-6-membered carbocyclic ring, thenR^(f) is hydrogen or deuterium;

Y^(1a) and Y^(1b) are each independently selected from hydrogen,deuterium and fluorine;

Y^(2a) and Y^(2b) are each independently selected from hydrogen anddeuterium;

Y^(3a) and Y^(3b) are each independently selected from hydrogen anddeuterium;

Y^(4a) and Y^(4b) are each independently selected from hydrogen anddeuterium;

Y^(5a) and Y^(5b) are each independently selected from hydrogen anddeuterium;

Y^(6a) and Y^(6b) are each independently selected from hydrogen anddeuterium;

Y^(7a) and Y^(7b) are each independently selected from hydrogen anddeuterium;

Y⁸ is selected from hydrogen and deuterium;

Y⁹ is selected from hydrogen and deuterium;

and

R¹ is selected from —CH₃, —CDH₂, —CD₂H, and —CD₃; provided that wheneach of Y^(1a), Y^(1b), Y^(2a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), Y^(4b),Y^(5a), Y^(5b), Y^(6a), Y^(6b), Y^(7a), Y^(7b), Y⁸ and Y⁹ is hydrogen,R¹ comprises at least one deuterium.

In one embodiment, the present invention provides a compound of FormulaA:

or a pharmaceutically acceptable salt thereof, wherein:

R^(a), R^(b) and R^(c) are each independently selected from —CH₃, —CDH₂,—CD₂H, and —CD₃;

Y^(1a) and Y^(1b) are each independently selected from hydrogen,deuterium and fluorine;

Y^(2a) and Y^(2b) are each independently selected from hydrogen anddeuterium;

Y^(3a) and Y^(3b) are each independently selected from hydrogen anddeuterium;

Y^(4a) and Y^(4b) are each independently selected from hydrogen anddeuterium;

Y^(5a) and Y^(5b) are each independently selected from hydrogen anddeuterium;

Y^(6a) and Y^(6b) are each independently selected from hydrogen anddeuterium;

Y^(7a) and Y^(7b) are each independently selected from hydrogen anddeuterium;

Y⁸ is selected from hydrogen and deuterium;

Y⁹ is selected from hydrogen and deuterium;

and

R¹ is selected from —CH₃, —CDH₂, —CD₂H, and —CD₃;

provided that when each of Y¹, Y^(1b), Y^(2a), Y^(2b), Y^(3a), Y^(3b),Y^(4a), Y^(4b), Y^(5a), Y^(5b), Y^(6a), Y^(6b), Y^(7a), Y^(7b), Y⁸ andY⁹ is hydrogen, R¹ comprises at least one deuterium.

In one embodiment, the compound of Formula A is a compound of Formula I:

or a pharmaceutically acceptable salt thereof.

In one embodiment, the compound of Formula B is a compound of FormulaB-I:

or a pharmaceutically acceptable salt thereof

In one embodiment of the compound of Formula I, R^(a), R^(b) and R^(c)are each —CH₃; Y^(1a) and Y^(1b) are the same; Y^(2a) and Y^(2b) are thesame; and R¹ is selected from —CH₃ and —CD₃. In one aspect of thisembodiment Y^(1a) and Y^(1b) are each deuterium. In another aspectY^(1a) and Y^(1b) are each hydrogen. In another aspect Y^(1a) and Y^(1b)are each fluorine. In one aspect of this embodiment, Y^(2a) and Y^(2b)are each deuterium. In another aspect Y^(2a) and Y^(2b) are eachhydrogen. In one aspect of this embodiment, R¹ is —CH₃. In anotheraspect R¹ is —CD₃. In one aspect of this embodiment, Y^(3a) and Y^(3b)are each deuterium. In another aspect Y^(3a) and Y^(3b) are eachhydrogen. In one aspect of this embodiment, when each of Y^(1a), Y^(1b),Y^(2a) and Y^(2b) is hydrogen, R¹ is —CD₃.

In one embodiment of the compound of Formula B-I, R^(a) and R^(b) areeach —CH₃; Y^(1a) and Y^(1b) are the same; Y^(2a) and Y^(2b) are thesame; and R¹ is selected from —CH₃ and —CD₃. In one aspect of thisembodiment Y^(1a) and Y^(1b) are each deuterium. In another aspectY^(1a) and Y^(1b) are each hydrogen. In another aspect Y^(1a) and Y^(1b)are each fluorine. In one aspect of this embodiment, Y^(2a) and Y^(2b)are each deuterium. In another aspect Y^(2a) and Y^(2b) are eachhydrogen. In one aspect of this embodiment, R¹ is —CH₃. In anotheraspect R¹ is —CD₃. In one aspect of this embodiment, Y^(3a) and Y^(3b)are each deuterium. In another aspect Y^(3a) and Y^(3b) are eachhydrogen. In one aspect of this embodiment, when each of Y^(1a), Y^(1b),Y^(2a) and Y^(2b) is hydrogen, R¹ is —CD₃.

In one embodiment of the compound of Formula I, R^(a), R^(b) and R^(c)are each —CH₃; Y^(1a) is fluorine; Y^(1b) is selected from hydrogen anddeuterium; Y^(2a) and Y^(2b) are the same; and R¹ is selected from —CH₃and —CD₃. In one aspect of this embodiment Y^(1b) is deuterium. Inanother aspect Y^(1b) is hydrogen. In one aspect of this embodiment,Y^(2a) and Y^(2b) are each deuterium. In another aspect Y^(2a) andY^(2b) are each hydrogen. In one aspect of this embodiment, R¹ is —CH₃.In another aspect R¹ is —CD₃. In one aspect of this embodiment, Y^(3a)and Y^(3b) are each deuterium. In another aspect Y^(3a) and Y^(3b) areeach hydrogen.

In one embodiment of the compound of Formula B-I, R^(a) and R^(b) areeach —CH₃; Y^(1a) is fluorine; Y^(1b) is selected from hydrogen anddeuterium; Y^(2a) and Y^(2b) are the same; and R¹ is selected from —CH₃and —CD₃. In one aspect of this embodiment Y^(1b) is deuterium. Inanother aspect Y^(1b) is hydrogen. In one aspect of this embodiment,Y^(2a) and Y^(2b) are each deuterium. In another aspect Y^(2a) andY^(2b) are each hydrogen. In one aspect of this embodiment, R¹ is —CH₃.In another aspect R¹ is —CD₃. In one aspect of this embodiment, Y^(3a)and Y^(3b) are each deuterium. In another aspect Y^(3a) and Y^(3b) areeach hydrogen.

In one embodiment of the compound of Formula I, R^(a), R^(b) and R^(c)are each —CH₃; and R¹ is selected from —CH₃ and —CD₃. In one aspect ofthis embodiment R¹ is —CH₃. In another aspect R¹ is —CD₃. In one aspectof this embodiment, Y^(2a) and Y_(2b) are each deuterium. In anotheraspect Y^(2a) and Y^(2b) are each hydrogen. In one aspect of thisembodiment, Y^(3a) and Y^(3b) are each deuterium. In another aspectY^(3a) and Y^(3b) are each hydrogen.

In one embodiment of the compound of Formula B-I, R^(a) and R^(b) areeach —CH₃; and R¹ is selected from —CH₃ and —CD₃. In one aspect of thisembodiment R¹ is —CH₃. In another aspect R¹ is —CD₃. In one aspect ofthis embodiment, Y^(2a) and Y^(2b) are each deuterium. In another aspectY^(2a) and Y^(2b) are each hydrogen. In one aspect of this embodiment,Y^(3a) and Y^(3b) are each deuterium. In another aspect Y^(3a) andY^(3b) are each hydrogen.

In another set of embodiments, any atom not designated as deuterium inany of the embodiments set forth above is present at its naturalisotopic abundance.

In one embodiment, the compound of Formula I is selected from any one ofthe compounds (Cmpd) set forth in Table 1a below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 1a Examples of Compounds of Formula I wherein R^(a), R^(b) andR^(c) are each —CH₃; each Y⁴ is hydrogen; each Y¹ is the same; each Y²is the same; and each Y³ is the same. Cmpd # Each Y¹ R¹ Each Y² Each Y³100 D CH₃ H H 101 D CD₃ H H 102 D CH₃ D H 103 D CD₃ D H 104 F CH₃ H H105 F CD₃ H H 106 F CH₃ D H 107 F CD₃ D H 108 H CD₃ H H 109 H CH₃ D H110 H CD₃ D H 111 D CH₃ H D 112 D CD₃ H D 113 D CH₃ D D 114 D CD₃ D D115 F CH₃ H D 116 F CD₃ H D 117 F CH₃ D D 118 F CD₃ D D 119 H CD₃ H D120 H CH₃ D D 121 H CD₃ D D

In one embodiment, the compound of Formula I is selected from any one ofthe compounds (Cmpd) set forth in Table 1b below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 1b Examples of Compounds of Formula I wherein R^(a), R^(b) andR^(c) are each —CH₃; each Y⁴ is deuterium; each Y¹ is the same; each Y²is the same; and each Y³ is the same. Cmpd # Each Y¹ R¹ Each Y² Each Y³500 D CH₃ H H 501 D CD₃ H H 502 D CH₃ D H 503 D CD₃ D H 504 F CH₃ H H505 F CD₃ H H 506 F CH₃ D H 507 F CD₃ D H 508 H CD₃ H H 509 H CH₃ D H510 H CD₃ D H 511 D CH₃ H D 512 D CD₃ H D 513 D CH₃ D D 514 D CD₃ D D515 F CH₃ H D 516 F CD₃ H D 517 F CH₃ D D 518 F CD₃ D D 519 H CD₃ H D520 H CH₃ D D 521 H CD₃ D D

In one embodiment, the compound of Formula A is selected from any one ofthe compounds (Cmpd) set forth in Table 1c below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 1c Examples of Compounds of Formula A wherein R^(a), R^(b) andR^(c) are each —CH₃; each Y⁴ is deuterium; each Y¹ is the same; each Y²is the same; each Y³ is the same; each Y⁵ is hydrogen; each Y⁶ isdeuterium; each Y⁷ is deuterium; each Y⁸ is hydrogen; and each Y⁹ ishydrogen: Cmpd # Each Y¹ R¹ Each Y² Each Y³ 600 D CH₃ H H 601 D CD₃ H H602 D CH₃ D H 603 D CD₃ D H 604 F CH₃ H H 605 F CD₃ H H 606 F CH₃ D H607 F CD₃ D H 608 H CD₃ H H 609 H CH₃ D H 610 H CD₃ D H 611 D CH₃ H D612 D CD₃ H D 613 D CH₃ D D 614 D CD₃ D D 615 F CH₃ H D 616 F CD₃ H D617 F CH₃ D D 618 F CD₃ D D 619 H CD₃ H D 620 H CH₃ D D 621 H CD₃ D D

In one embodiment, the compound of Formula I is selected from any one ofthe compounds (Cmpd) set forth in Table 2 below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 2 Examples of Compounds of Formula I wherein R^(a), R^(b) andR^(c) are each —CH₃, Y^(1a) is fluorine and Y^(1b) is hydrogen ordeuterium; each Y⁴ is hydrogen; each Y² is the same; and each Y³ is thesame Cmpd # Y^(1b) R¹ Each Y² Each Y³ 200 D CH₃ H H 201 D CD₃ H H 202 DCH₃ D H 203 D CD₃ D H 204 H CH₃ H H 205 H CD₃ H H 206 H CH₃ D H 207 HCD₃ D H 208 D CH₃ H D 209 D CD₃ H D 210 D CH₃ D D 211 D CD₃ D D 212 HCH₃ H D 213 H CD₃ H D 214 H CH₃ D D 215 H CD₃ D D

In one embodiment, the compound of Formula I is selected from any one ofthe compounds (Cmpd) set forth in Table 2 above, wherein thestereochemistry at the carbon bearing Y^(1a) and Y^(1b) is (R), or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance.

In one embodiment, the compound of Formula I is selected from any one ofthe compounds (Cmpd) set forth in Table 2 above, wherein thestereochemistry at the carbon bearing Y^(1a) and Y^(1b) is (5), or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance.

In one embodiment, the compound of Formula B-I is selected from any oneof the compounds (Cmpd) set forth in Table 3 below, or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance:

TABLE 3 Examples of Compounds of Formula B-I wherein R^(a) and R^(b) areeach —CH₃; each Y⁴ is hydrogen; each Y¹ is the same; each Y² is thesame; and each Y³ is the same. Cmpd # Each Y¹ R¹ Each Y² Each Y³ 300 DCH₃ H H 301 D CD₃ H H 302 D CH₃ D H 303 D CD₃ D H 304 F CH₃ H H 305 FCD₃ H H 306 F CH₃ D H 307 F CD₃ D H 308 H CD₃ H H 309 H CH₃ D H 310 HCD₃ D H 311 D CH₃ H D 312 D CD₃ H D 313 D CH₃ D D 314 D CD₃ D D 315 FCH₃ H D 316 F CD₃ H D 317 F CH₃ D D 318 F CD₃ D D 319 H CD₃ H D 320 HCH₃ D D 321 H CD₃ D D

In one embodiment, the compound of Formula B-I is selected from any oneof the compounds (Cmpd) set forth in Table 4 below, or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance:

TABLE 4 Examples of Compounds of Formula B-I wherein R^(a) and R^(b) areeach —CH₃, Y^(1a) is fluorine and Y^(1b) is hydrogen or deuterium; eachY⁴ is hydrogen; each Y² is the same; and each Y³ is the same Cmpd #Y^(1b) R¹ Each Y² Each Y³ 400 D CH₃ H H 401 D CD₃ H H 402 D CH₃ D H 403D CD₃ D H 404 H CH₃ H H 405 H CD₃ H H 406 H CH₃ D H 407 H CD₃ D H 408 DCH₃ H D 409 D CD₃ H D 410 D CH₃ D D 411 D CD₃ D D 412 H CH₃ H D 413 HCD₃ H D 414 H CH₃ D D 415 H CD₃ D D

In one embodiment, the compound of Formula B-I is selected from any oneof the compounds (Cmpd) set forth in Table 4 above, wherein thestereochemistry at the carbon bearing Y^(1a) and Y^(1b) is (R), or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance.

In one embodiment, the compound of Formula B-I is selected from any oneof the compounds (Cmpd) set forth in Table 4 above, wherein thestereochemistry at the carbon bearing Y^(1a) and Y^(1b) is (5), or apharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium in any of the compounds set forth therein ispresent at its natural isotopic abundance.

In one embodiment of the present invention, the compound of Formula B isa compound of Formula C:

or a pharmaceutically acceptable salt thereof, wherein

R^(d) and R^(e) are each independently hydrogen or deuterium; or R^(d)and R^(e) taken together with the carbon to which they are connectedform a 3-membered carbocyclic ring that is optionally substituted withdeuterium;

provided that if R^(d) and R^(e) are each independently hydrogen ordeuterium, then R^(f) is OR^(c) wherein R^(c) is selected from —CH₃ and—CD₃;

and provided that if R^(d) and R^(e) taken together with the carbon towhich they are connected form a 3-membered carbocyclic ring, then R^(f)is hydrogen or deuterium;

Y^(3a) and Y^(3b) are each independently selected from hydrogen anddeuterium;

Y^(5a) and Y^(5b) are each independently selected from hydrogen anddeuterium;

Y⁸ is selected from hydrogen and deuterium;

Y⁹ is selected from hydrogen and deuterium;

R¹ is selected from —CH₃ and —CD₃; and

each of Y^(2a), Y^(2b), Y^(6a), Y^(6b), Y^(7a) and Y^(7b) is the sameand is either hydrogen or deuterium.

In one embodiment, the compound of Formula C is selected from any one ofthe compounds (Cmpd) set forth in Table 5a below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 5a Examples of Compounds of Formula C wherein Y⁸, Y⁹ are eachhydrogen; R^(a) and R^(b) are each —CH₃, and each of Y^(3a), Y^(3b),Y^(5a), and Y^(5b) is hydrogen Cmpd # R¹ Each of Y^(2a), Y^(2b), Y^(6a),Y^(6b), Y^(7a) and Y^(7b)

701a CH₃ D CH₂OCH₃ 702a CD₃ H CH₂OCH₃ 703a CD₃ D CH₂OCH₃ 704a CH₃ Hcyclopropyl 705a CH₃ D cyclopropyl 706a CD₃ H cyclopropyl 707a CD₃ Dcyclopropyl

In one embodiment, the compound of Formula C is selected from any one ofthe compounds (Cmpd) set forth in Table 5b below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 5b Examples of Compounds of Formula C wherein Y⁸, Y⁹ are eachhydrogen; R^(a) and R^(b) are each —CH₃, and each of Y^(3a), Y^(3b),Y^(5a), and Y^(5b) is deuterium Cmpd # R^(l) Each of Y^(2a), Y^(2b),Y^(6a), Y^(6b), Y^(7a) and Y^(7b)

700b CH₃ H CH₂OCH₃ 701b CH₃ D CH₂OCH₃ 702b CD₃ H CH₂OCH₃ 703b CD₃ DCH₂OCH₃ 704b CH₃ H cyclopropyl 705b CH₃ D cyclopropyl 706b CD₃ Hcyclopropyl 707  CD₃ D cyclopropyl

In one embodiment, the compound of Formula B is selected from any one ofthe compounds (Cmpd) set forth in Table 6a below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 6a Examples of Compounds of Formula B wherein R^(a) and R^(b) areeach —CH₃, each Y¹ is fluorine; Y⁸ is hydrogen; and Y⁹ is hydrogen Cmpd# Each of Y^(2a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), Y^(4b), Y^(5a),Y^(5b), Y^(6a), Y^(6b), Y^(7a), and Y^(7b), R¹

800a H CH₃ CH₂OCH₃ 801a H CD₃ CH₂OCH₃ 802a D CH₃ CH₂OCH₃ 803a D CD₃CH₂OCH₃ 804a H CH₃ cyclopropyl 805a H CD₃ cyclopropyl 806a D CH₃cyclopropyl 807a D CD₃ cyclopropyl

In one embodiment, the compound of Formula B is selected from any one ofthe compounds (Cmpd) set forth in Table 6b below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 6b Examples of Compounds of Formula B wherein R^(a) and R^(b) areeach —CH₃, each Y¹ is deuterium; Y⁸ is hydrogen; and Y⁹ is hydrogen Cmpd# Each of Y^(2a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), Y^(4b), Y^(5a),Y^(5b), Y^(6a), Y^(6b), Y^(7a), and Y^(7b), R¹

800b H CH₃ CH₂OCH₃ 801b H CD₃ CH₂OCH₃ 802b D CH₃ CH₂OCH₃ 803b D CD₃CH₂OCH₃ 804b H CH₃ cyclopropyl 805b H CD₃ cyclopropyl 806b D CH₃cyclopropyl 807b D CD₃ cyclopropyl

In one embodiment, the compound of Formula B is selected from any one ofthe compounds (Cmpd) set forth in Table 6c below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium inany of the compounds set forth therein is present at its naturalisotopic abundance:

TABLE 6c Examples of Compounds of Formula B wherein R^(a) and R^(b) areeach —CH₃, each Y¹ is hydrogen; Y⁸ is hydrogen; and Y⁹ is hydrogen Cmpd# Each of Y^(2a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), Y^(4b), Y^(5a),Y^(5b), Y^(6a), Y^(6b), Y^(7a), and Y^(7b), R¹

801c H CD₃ CH₂OCH₃ 802c D CH₃ CH₂OCH₃ 803c D CD₃ CH₂OCH₃ 805c H CD₃cyclopropyl 806c D CH₃ cyclopropyl 807c D CD₃ cyclopropyl

In one embodiment the invention is directed to compounds of FormulaIIa-d or salts thereof:

wherein PG in IIc is a protecting group such as (i) (C₆-C₁₀ aryl)CH₂—,such as benzyl or (ii) C₁-C₆ alkyl-OC(O)—, such as Boc(t-butoxycarbonyl);and

wherein Z in IId is a leaving group, such as halogen; (C₁-C₆ alkyl)-SO₃wherein the C₁-C₆ alkyl is optionally substituted with halogen; and(C₆-C₁₀ aryl)-SO₃ wherein the C₆-C₁₀ aryl is optionally substituted withalkyl, halogen, or a combination thereof, provided that (a) in IIa, IIb,and IIc, when each Y is hydrogen, then R¹ comprises at least onedeuterium; and (b) in IId, at least one Y is deuterium. In oneembodiment, any atom not designated as deuterium in any of IIa-IId ispresent at its natural isotopic abundance.

The synthesis of compounds of Formula B, Formula A, Formula I andFormula B-I may be readily achieved by synthetic chemists of ordinaryskill by reference to the Exemplary Synthesis and Examples disclosedherein. Relevant procedures analogous to those of use for thepreparation of compounds of Formula B, Formula A, Formula I, Formula B-Iand intermediates thereof are disclosed, for instance in U.S. Pat. No.4,808,605, U.S. Pat. No. 5,808,088 and PCT Publication No. WO 98/49148.

Such methods can be carried out utilizing corresponding deuterated andoptionally, other isotope-containing reagents and/or intermediates tosynthesize the compounds delineated herein, or invoking standardsynthetic protocols known in the art for introducing isotopic atoms to achemical structure.

Exemplary Synthesis

Compounds of Formula B, Formula A, Formula I and Formula B-I may beconveniently prepared in a manner analogous to that described in U.S.Pat. No. 4,808,605 (the “'605 patent”) by replacing the reagents and/orstarting materials described in the schemes and the examples in the '605patent with suitable deuterated counterparts to obtain derivatives ofmibefradil having the deuteration patterns disclosed herein. Forexample, the deuterated counterparts of the reagents and/or startingmaterials described in the schemes and examples of the '605 patent maybe commercially available deuterated compounds. The schemes of the '605patent, shown on column 7, line 7-column 12, line 57, and the examplesof the '605 patent, shown on column 16, line 1-column 40, line 51, areincorporated by reference herein. Compounds of Formula B, Formula A,Formula I and Formula B-I may also be conveniently prepared in a manneranalogous to the one described in U.S. Pat. No. 5,808,088 (the “'088patent”) by replacing the reagents and/or starting materials describedin the schemes and the examples in the '088 patent with suitabledeuterated counterparts to obtain derivatives of mibefradil having thedeuteration patterns disclosed herein. For example, the deuteratedcounterparts of the reagents and/or starting materials described in theschemes and examples of the '088 patent may be commercially availabledeuterated compounds. The disclosure of the '088 patent from col. 1,line 65 to col. 3, line 2; column 3, lines 3-column 6, line 60, and theexample of the '088 patent, shown on column 6, line 61-column 9, line57, are incorporated by reference herein. Compounds of Formula B,Formula A, Formula I and Formula B-I may also be conveniently preparedin a manner analogous to the one described in PCT Publication No. WO98/49148 (the “'148 patent”) by replacing the reagents and/or startingmaterials described in the schemes and the examples in the '148 patentwith suitable deuterated counterparts to obtain derivatives ofmibefradil having the deuteration patterns disclosed herein. Forexample, the deuterated counterparts of the reagents and/or startingmaterials described in the schemes and examples of the '148 patent maybe commercially available deuterated compounds. The disclosure of the'148 patent from page 2, line 4-page 4, line 7; page 4, line 10-page 9,line 35, and the example of the '148 patent, shown on page 10, line1-page 15-line 26, are incorporated by reference herein. Compounds ofFormula B, Formula A, Formula I and Formula B-I may also be convenientlyprepared in a manner analogous to the one described in Casas et al.,Drugs of the Future 1997, Vol. 22, p. 1091-1102 by replacing thereagents and/or starting materials described in the schemes and theexamples with suitable deuterated counterparts to obtain derivatives ofmibefradil having the deuteration patterns disclosed herein. Forexample, the deuterated counterparts of the reagents and/or startingmaterials described in the schemes and examples of Casas et al. may becommercially available deuterated compounds. The disclosure of Casas etal. on page 1091 and on page 1092 (Scheme 1) is incorporated byreference herein. Such approaches are not intended to be limiting.

Scheme 1 below outlines a general route for preparing compounds ofFormula B, Formula A, Formula I and Formula B-I.

Scheme 1 depicts a general route to compounds of Formula B following thegeneral methods of Hengartner, U. et al., U.S. Pat. No. 4,680,310; andthe '148 patent. Deuterated carboxylic acid 10 may be converted to theacid chloride and coupled with deuterated ethylene 11 using theprocedure described by Hengartner, U. et al., U.S. Pat. No. 4,680,310 toafford ketone 12. The remaining steps can be performed under conditionspreviously described by the '148 patent. Condensation of 12 with thelithium enolate of deuterated ester 13 (wherein Y¹⁰, Y^(5a), and Y^(5b)are the same and are either hydrogen or deuterium) affords alcohol 14.Acidic cleavage of the tert-butyl ester with formic acid, formation ofthe mixed anhydride with pivaloyl chloride and coupling with deuteratedamine 16 (compounds of Formula IIb) affords amide 17. Reductive removalof the carbonyl group with Red-Al followed by coupling of the alcoholmoiety with acid chloride 18 affords compounds of Formula B. One skilledin the art will appreciate that deuterated solvents and reagents may besubstituted, where appropriate, to afford compounds of Formula B bearingdifferent patterns of deuterium substitution.

As an example, the pathway shown in Scheme I may be useful to obtaincompounds of Formula A wherein each Y¹ and each Y⁴ is deuterium.

The following intermediates that may be used in Scheme 1 above arecommercially available:

Additional useful intermediates may be prepared as outlined in theschemes below. One skilled in the art will appreciate that deuteratedsolvents and reagents may be substituted, where appropriate, to affordintermediates bearing different patterns of deuterium substitution.

Intermediate 16a may be prepared from pyrrolidinone 19a as shown inScheme 2 above. Following the protocol described in Galakatos, N. G. etal., J. Org. Chem. 1985, 50, 1302-1304, the pyrrolidinone ring of 19amay be opened with Ba(OH)₂ and the resulting free amine protected withCBzCl to afford carbamate 21. The remaining steps can be performed underconditions previously described in Shin, K. J. et al., Biorg. Med. Chem.Lett. 2008, 18, 4424-4427. The carboxylic acid moiety of 21 may beactivated with isobutyl chloroformate and then coupled withbenzene-1,2-diamine to afford amide 24. Cyclization to formbenzimidazole 25 may be effected under acidic conditions, followingwhich hydrogenolysis of the carbamate with Pd/C affords intermediate16a.

Intermediate 19b may be prepared as shown in Scheme 3 above according tothe method of Djerassi, C. et al., J. Am. Chem. Soc. 1964, 86,5536-5541. Reduction of a single carbonyl group ofcommercially-available succinimide 26 with LiAlD₄ followed by alkylationof the nitrogen atom with CD₃I affords pyrrolidinone 19b. 19b may bethen converted to 16b in accordance with the procedure of Scheme 2 usedto convert 19a to 16a.

Similarly, 16c and 16d may be prepared using appropriately deuteratedsolvents and reagents:

The preparation of fluorinated intermediate 12b is shown in Scheme 4aabove. Following conditions previously described in Krueger, A. C. etal., Biorg. Med. Chem. Lett. 2007, 17, 2289-2292, ketone 12a (preparedas in Scheme 1 above from 2-(4-fluorophenyl)-3-methyl-butyric acid andethylene) is converted to enone 29 via conversion to enol ether 28followed by palladium dichromate-mediated oxidation to 29. Treatment of29 with diethylaminosulfur trifluoride (DAST) affords 30. Basichydrolysis of the enol ether moiety affords 12b. 12b may be thenconverted to a Compound of Formula B wherein each Y¹ is fluorine inaccordance with Scheme 1 above.

An alternative preparation of fluorinated intermediate 12b is shown inScheme 4b above. 51 is treated with XtalFluor, such as XtalFluor-E orXtalFluor-M, disclosed athttp://www.sigmaaldrich.com/sigma-aldrich/technical-documents/articles/chemfiles/xtalfluor-e-and-xtalfluor-m.html,to afford 52. Other fluorinating agents that may be used to afford 52are within the purview of one skilled in the art. Oxidation of 52 withKMnO₄ in a manner analogous to the one described in WO1996/26181 affords53. Silylation of 53 followed by oxidation with mCPBA in a manneranalogous to that of J. Am. Chem. Soc., 107(15), 4577-9; 1985 provides54, which on treatment with isopropyl magnesium iodide is converted to55. Treatment of 55 with HF-pyridine gives 56, which is then treatedwith hydrogen in the presence of Ru/BINAP to yield 57. Other chiralcatalysts may be used to afford 57.

The preparation of deuterated intermediate (S)-12c is shown in Scheme 5above. Following a protocol previously described in Scalone, M. et al.,Tetrahedron Asymm. 1997, 8, 3617-3623, i-PrMgCl-mediated aldol additionof commercially-available 31 to acetone-d₆ followed by acid-catalyzeddehydration of the aldol product affords crotonic acid 32.Palladium-mediated deuterogenation of the alkene moiety affords 12c.Chiral separation of the enantiomers of 12c affords (S)-12c.

A possible route for the preparation of deuterated intermediate 18a isshown in Scheme 6 above. Acid-catalyzed hydrogen-deuterium exchange atthe α-carbon affords acid 34. Treatment of 34 with oxalyl chlorideaffords acid chloride 18a.

Additional methods of synthesizing compounds of Formula B, Formula A,Formula I and Formula B-I and their synthetic precursors, includingthose within routes not explicitly shown in schemes herein, are withinthe means of chemists of ordinary skill in the art. Synthetic chemistrytransformations and protecting group methodologies (protection anddeprotection) useful in synthesizing the applicable compounds are knownin the art and include, for example, those described in Larock R,Comprehensive Organic Transformations, VCH Publishers (1989); Greene, TW et al., Protective Groups in Organic Synthesis, ^(3rd) Ed., John Wileyand Sons (1999); Fieser, L et al., Fieser and Fieser's Reagents forOrganic Synthesis, John Wiley and Sons (1994); and Paquette, L, ed.,Encyclopedia of Reagents for Organic Synthesis, John Wiley and Sons(1995) and subsequent editions thereof.

Combinations of substituents and variables envisioned by this inventionare only those that result in the formation of stable compounds.

Compositions

The invention also provides pyrogen-free pharmaceutical compositionscomprising an effective amount of a compound of Formula B, Formula A,Formula I or Formula B-I (e.g., including any of the formulae herein),or a pharmaceutically acceptable salt of said compound; and apharmaceutically acceptable carrier. The carrier(s) are “acceptable” inthe sense of being compatible with the other ingredients of theformulation and, in the case of a pharmaceutically acceptable carrier,not deleterious to the recipient thereof in an amount used in themedicament.

Pharmaceutically acceptable carriers, adjuvants and vehicles that may beused in the pharmaceutical compositions of this invention include, butare not limited to, ion exchangers, alumina, aluminum stearate,lecithin, serum proteins, such as human serum albumin, buffer substancessuch as phosphates, glycine, sorbic acid, potassium sorbate, partialglyceride mixtures of saturated vegetable fatty acids, water, salts orelectrolytes, such as protamine sulfate, disodium hydrogen phosphate,potassium hydrogen phosphate, sodium chloride, zinc salts, colloidalsilica, magnesium trisilicate, polyvinyl pyrrolidone, cellulose-basedsubstances, polyethylene glycol, sodium carboxymethylcellulose,polyacrylates, waxes, polyethylene-polyoxypropylene-block polymers,polyethylene glycol and wool fat.

If required, the solubility and bioavailability of the compounds of thepresent invention in pharmaceutical compositions may be enhanced bymethods well-known in the art. One method includes the use of lipidexcipients in the formulation. See “Oral Lipid-Based Formulations:Enhancing the Bioavailability of Poorly Water-Soluble Drugs (Drugs andthe Pharmaceutical Sciences),” David J. Hauss, ed. Informa Healthcare,2007; and “Role of Lipid Excipients in Modifying Oral and ParenteralDrug Delivery: Basic Principles and Biological Examples,” Kishor M.Wasan, ed. Wiley-Interscience, 2006.

Another known method of enhancing bioavailability is the use of anamorphous form of a compound of this invention optionally formulatedwith a poloxamer, such as LUTROL™ and PLURONIC™ (BASF Corporation), orblock copolymers of ethylene oxide and propylene oxide. See U.S. Pat.No. 7,014,866; and United States patent publications 20060094744 and20060079502.

The pharmaceutical compositions of the invention include those suitablefor oral, rectal, nasal, topical (including buccal and sublingual),vaginal or parenteral (including subcutaneous, intramuscular,intravenous and intradermal) administration. In certain embodiments, thecompound of the formulae herein is administered transdermally (e.g.,using a transdermal patch or iontophoretic techniques). Otherformulations may conveniently be presented in unit dosage form, e.g.,tablets, sustained release capsules, and in liposomes, and may beprepared by any methods well known in the art of pharmacy. See, forexample, Remington: The Science and Practice of Pharmacy, LippincottWilliams & Wilkins, Baltimore, Md. (20th ed. 2000).

Such preparative methods include the step of bringing into associationwith the molecule to be administered ingredients such as the carrierthat constitutes one or more accessory ingredients. In general, thecompositions are prepared by uniformly and intimately bringing intoassociation the active ingredients with liquid carriers, liposomes orfinely divided solid carriers, or both, and then, if necessary, shapingthe product.

In certain embodiments, the compound is administered orally.Compositions of the present invention suitable for oral administrationmay be presented as discrete units such as capsules, sachets, or tabletseach containing a predetermined amount of the active ingredient; apowder or granules; a solution or a suspension in an aqueous liquid or anon-aqueous liquid; an oil-in-water liquid emulsion; a water-in-oilliquid emulsion; packed in liposomes; or as a bolus, etc. Soft gelatincapsules can be useful for containing such suspensions, which maybeneficially increase the rate of compound absorption.

In the case of tablets for oral use, carriers that are commonly usedinclude lactose and corn starch. Lubricating agents, such as magnesiumstearate, are also typically added. For oral administration in a capsuleform, useful diluents include lactose and dried cornstarch. When aqueoussuspensions are administered orally, the active ingredient is combinedwith emulsifying and suspending agents. If desired, certain sweeteningand/or flavoring and/or coloring agents may be added.

Compositions suitable for oral administration include lozengescomprising the ingredients in a flavored basis, usually sucrose andacacia or tragacanth; and pastilles comprising the active ingredient inan inert basis such as gelatin and glycerin, or sucrose and acacia.

Compositions suitable for parenteral administration include aqueous andnon-aqueous sterile injection solutions which may contain anti-oxidants,buffers, bacteriostats and solutes which render the formulation isotonicwith the blood of the intended recipient; and aqueous and non-aqueoussterile suspensions which may include suspending agents and thickeningagents. The formulations may be presented in unit-dose or multi-dosecontainers, for example, sealed ampules and vials, and may be stored ina freeze dried (lyophilized) condition requiring only the addition ofthe sterile liquid carrier, for example water for injections,immediately prior to use. Extemporaneous injection solutions andsuspensions may be prepared from sterile powders, granules and tablets.

Such injection solutions may be in the form, for example, of a sterileinjectable aqueous or oleaginous suspension. This suspension may beformulated according to techniques known in the art using suitabledispersing or wetting agents (such as, for example, Tween 80) andsuspending agents. The sterile injectable preparation may also be asterile injectable solution or suspension in a non-toxicparenterally-acceptable diluent or solvent, for example, as a solutionin 1,3-butanediol. Among the acceptable vehicles and solvents that maybe employed are mannitol, water, Ringer's solution and isotonic sodiumchloride solution. In addition, sterile, fixed oils are conventionallyemployed as a solvent or suspending medium. For this purpose, any blandfixed oil may be employed including synthetic mono- or diglycerides.Fatty acids, such as oleic acid and its glyceride derivatives are usefulin the preparation of injectables, as are naturalpharmaceutically-acceptable oils, such as olive oil or castor oil,especially in their polyoxyethylated versions. These oil solutions orsuspensions may also contain a long-chain alcohol diluent or dispersant.

The pharmaceutical compositions of this invention may be administered inthe form of suppositories for rectal administration. These compositionscan be prepared by mixing a compound of this invention with a suitablenon-irritating excipient which is solid at room temperature but liquidat the rectal temperature and therefore will melt in the rectum torelease the active components. Such materials include, but are notlimited to, cocoa butter, beeswax and polyethylene glycols.

The pharmaceutical compositions of this invention may be administered bynasal aerosol or inhalation. Such compositions are prepared according totechniques well-known in the art of pharmaceutical formulation and maybe prepared as solutions in saline, employing benzyl alcohol or othersuitable preservatives, absorption promoters to enhance bioavailability,fluorocarbons, and/or other solubilizing or dispersing agents known inthe art. See, e.g.: Rabinowitz J D and Zaffaroni A C, U.S. Pat. No.6,803,031, assigned to Alexza Molecular Delivery Corporation.

Topical administration of the pharmaceutical compositions of thisinvention is especially useful when the desired treatment involves areasor organs readily accessible by topical application. For topicalapplication topically to the skin, the pharmaceutical composition shouldbe formulated with a suitable ointment containing the active componentssuspended or dissolved in a carrier. Carriers for topical administrationof the compounds of this invention include, but are not limited to,mineral oil, liquid petroleum, white petroleum, propylene glycol,polyoxyethylene polyoxypropylene compound, emulsifying wax, and water.Alternatively, the pharmaceutical composition can be formulated with asuitable lotion or cream containing the active compound suspended ordissolved in a carrier. Suitable carriers include, but are not limitedto, mineral oil, sorbitan monostearate, polysorbate 60, cetyl esterswax, cetearyl alcohol, 2-octyldodecanol, benzyl alcohol, and water. Thepharmaceutical compositions of this invention may also be topicallyapplied to the lower intestinal tract by rectal suppository formulationor in a suitable enema formulation. Topically-transdermal patches andiontophoretic administration are also included in this invention.

Application of the subject therapeutics may be local, so as to beadministered at the site of interest. Various techniques can be used forproviding the subject compositions at the site of interest, such asinjection, use of catheters, trocars, projectiles, pluronic gel, stents,sustained drug release polymers or other device which provides forinternal access.

Thus, according to yet another embodiment, the compounds of thisinvention may be incorporated into compositions for coating animplantable medical device, such as prostheses, artificial valves,vascular grafts, stents, or catheters. Suitable coatings and the generalpreparation of coated implantable devices are known in the art and areexemplified in U.S. Pat. Nos. 6,099,562; 5,886,026; and 5,304,121. Thecoatings are typically biocompatible polymeric materials such as ahydrogel polymer, polymethyldisiloxane, polycaprolactone, polyethyleneglycol, polylactic acid, ethylene vinyl acetate, and mixtures thereof.The coatings may optionally be further covered by a suitable topcoat offluorosilicone, polysaccharides, polyethylene glycol, phospholipids orcombinations thereof to impart controlled release characteristics in thecomposition. Coatings for invasive devices are to be included within thedefinition of pharmaceutically acceptable carrier, adjuvant or vehicle,as those terms are used herein.

According to another embodiment, the invention provides a method ofcoating an implantable medical device comprising the step of contactingsaid device with the coating composition described above. It will beobvious to those skilled in the art that the coating of the device willoccur prior to implantation into a mammal.

According to another embodiment, the invention provides a method ofimpregnating an implantable drug release device comprising the step ofcontacting said drug release device with a compound or composition ofthis invention. Implantable drug release devices include, but are notlimited to, biodegradable polymer capsules or bullets, non-degradable,diffusible polymer capsules and biodegradable polymer wafers.

According to another embodiment, the invention provides an implantablemedical device coated with a compound or a composition comprising acompound of this invention, such that said compound is therapeuticallyactive.

According to another embodiment, the invention provides an implantabledrug release device impregnated with or containing a compound or acomposition comprising a compound of this invention, such that saidcompound is released from said device and is therapeutically active.

Where an organ or tissue is accessible because of removal from thesubject, such organ or tissue may be bathed in a medium containing acomposition of this invention, a composition of this invention may bepainted onto the organ, or a composition of this invention may beapplied in any other convenient way.

In another embodiment, a composition of this invention further comprisesa second therapeutic agent. The second therapeutic agent may be selectedfrom any compound or therapeutic agent known to have or thatdemonstrates advantageous properties when administered with a compoundhaving the same mechanism of action as mibefradil. Such agents includebeta blockers, aldose reductase inhibitors, NSAIDs, 5HT_(1D) agonists,dopamine D₂ receptor antagonists, secale alkaloids, a second calciumchannel blocker and neurokinin antagonists.

In another embodiment, the invention provides separate dosage forms of acompound of this invention and one or more of any of the above-describedsecond therapeutic agents, wherein the compound and second therapeuticagent are associated with one another. The term “associated with oneanother” as used herein means that the separate dosage forms arepackaged together or otherwise attached to one another such that it isreadily apparent that the separate dosage forms are intended to be soldand administered together (within less than 24 hours of one another,consecutively or simultaneously).

In the pharmaceutical compositions of the invention, the compound of thepresent invention is present in an effective amount. As used herein, theterm “effective amount” refers to an amount which, when administered ina proper dosing regimen, is sufficient to treat the target disorder.

The interrelationship of dosages for animals and humans (based onmilligrams per meter squared of body surface) is described in Freireichet al., Cancer Chemother. Rep, 1966, 50: 219. Body surface area may beapproximately determined from height and weight of the subject. See,e.g., Scientific Tables, Geigy Pharmaceuticals, Ardsley, N.Y., 1970,537.

In one embodiment, an effective amount of a compound of this inventioncan range from 10 mg to 200 mg per day, from 50-100 mg/day, or from20-50 mg/day.

Effective doses will also vary, as recognized by those skilled in theart, depending on the diseases treated, the severity of the disease, theroute of administration, the sex, age and general health condition ofthe subject, excipient usage, the possibility of co-usage with othertherapeutic treatments such as use of other agents and the judgment ofthe treating physician. For example, guidance for selecting an effectivedose can be determined by reference to the prescribing information formibefradil.

For pharmaceutical compositions that comprise a second therapeuticagent, an effective amount of the second therapeutic agent is betweenabout 20% and 100% of the dosage normally utilized in a monotherapyregime using just that agent. Preferably, an effective amount is betweenabout 70% and 100% of the normal monotherapeutic dose. The normalmonotherapeutic dosages of these second therapeutic agents are wellknown in the art. See, e.g., Wells et al., eds., PharmacotherapyHandbook, 2nd Edition, Appleton and Lange, Stamford, Conn. (2000); PDRPharmacopoeia, Tarascon Pocket Pharmacopoeia 2000, Deluxe Edition,Tarascon Publishing, Loma Linda, Calif. (2000), each of which referencesare incorporated herein by reference in their entirety.

It is expected that some of the second therapeutic agents referencedabove will act synergistically with the compounds of this invention.When this occurs, it will allow the effective dosage of the secondtherapeutic agent and/or the compound of this invention to be reducedfrom that required in a monotherapy. This has the advantage ofminimizing toxic side effects of either the second therapeutic agent ofa compound of this invention, synergistic improvements in efficacy,improved ease of administration or use and/or reduced overall expense ofcompound preparation or formulation.

Methods of Treatment

In another embodiment, the invention provides a method of modulating theactivity of calcium channel in a cell, comprising contacting a cell withone or more compounds of Formula B, Formula A, Formula I or Formula B-Iherein or pharmaceutically acceptable salts thereof.

According to another embodiment, the invention provides a method oftreating a disease that is beneficially treated by mibefradil in asubject in need thereof, comprising the step of administering to thesubject an effective amount of a compound or a composition of thisinvention. Such diseases include, but are not limited to anginapectoris, ischemia, arrhythmias, congestive heart failure, high bloodpressure, cardiac insufficiency, pain, visceral pain and diabeticcomplications (such as diabetic neuropathy, diabetic nephropathy,diabetic retinopathy, myocardial infarction, cataracts and diabeticcardiomyopathy).

In one particular embodiment, the method of this invention is used totreat a disease or condition selected from hypertension and anginapectoris in a subject in need thereof.

In another particular embodiment, the method of this invention is usedto treat congestive heart failure in a subject in need thereof.

Identifying a subject in need of such treatment can be in the judgmentof a subject or a health care professional and can be subjective (e.g.opinion) or objective (e.g. measurable by a test or diagnostic method).

In another embodiment, any of the above methods of treatment comprisesthe further step of co-administering to the subject in need thereof oneor more second therapeutic agents. The choice of second therapeuticagent may be made from any second therapeutic agent known to be usefulfor co-administration with mibefradil. The choice of second therapeuticagent is also dependent upon the particular disease or condition to betreated. Examples of second therapeutic agents that may be employed inthe methods of this invention are those set forth above for use incombination compositions comprising a compound of this invention and asecond therapeutic agent.

In particular, the invention provides a method of treating a disease orcondition selected from arrhythmias, hypertension and angina pectoris ina subject comprising the step of co-administering to the subject in needthereof a compound of Formula B, Formula A, Formula I or Formula B-I ora pharmaceutically acceptable salt of said compound, and a beta blocker.

In another embodiment, the invention provides a method of treating adiabetic complication in a subject comprising the step ofco-administering to the subject in need thereof a compound of Formula B,Formula A, Formula I or Formula B-I or a pharmaceutically acceptablesalt of said compound, and an aldose reductase inhibitor.

The term “co-administered” as used herein means that the secondtherapeutic agent may be administered together with a compound of thisinvention as part of a single dosage form (such as a composition of thisinvention comprising a compound of the invention and an secondtherapeutic agent as described above) or as separate, multiple dosageforms. Alternatively, the additional agent may be administered prior to,consecutively with, or following the administration of a compound ofthis invention. In such combination therapy treatment, both thecompounds of this invention and the second therapeutic agent(s) areadministered by conventional methods. The administration of acomposition of this invention, comprising both a compound of theinvention and a second therapeutic agent, to a subject does not precludethe separate administration of that same therapeutic agent, any othersecond therapeutic agent or any compound of this invention to saidsubject at another time during a course of treatment.

Effective amounts of these second therapeutic agents are well known tothose skilled in the art and guidance for dosing may be found in patentsand published patent applications referenced herein, as well as in Wellset al., eds., Pharmacotherapy Handbook, 2nd Edition, Appleton and Lange,Stamford, Conn. (2000); PDR Pharmacopoeia, Tarascon Pocket Pharmacopoeia2000, Deluxe Edition, Tarascon Publishing, Loma Linda, Calif. (2000),and other medical texts. However, it is well within the skilledartisan's purview to determine the second therapeutic agent's optimaleffective-amount range.

In one embodiment of the invention, where a second therapeutic agent isadministered to a subject, the effective amount of the compound of thisinvention is less than its effective amount would be where the secondtherapeutic agent is not administered. In another embodiment, theeffective amount of the second therapeutic agent is less than itseffective amount would be where the compound of this invention is notadministered. In this way, undesired side effects associated with highdoses of either agent may be minimized. Other potential advantages(including without limitation improved dosing regimens and/or reduceddrug cost) will be apparent to those of skill in the art.

In yet another aspect, the invention provides the use of a compound ofFormula B, Formula A, Formula I or Formula B-I or a pharmaceuticallyacceptable salt of the compound, alone or together with one or more ofthe above-described second therapeutic agents in the manufacture of amedicament, either as a single composition or as separate dosage forms,for treatment or prevention in a subject of a disease, disorder orsymptom set forth above. Another aspect of the invention is a compoundof Formula B, Formula A, Formula I or Formula B-I or a pharmaceuticallyacceptable salt of the compound, for use in the treatment or preventionin a subject of a disease, disorder or symptom thereof delineatedherein.

EXAMPLES

In the examples below, any atom not designated as deuterium is presentat its natural isotopic abundance.

Example 1 Preparation of2-((1S,2S)-3,3,4,4-Tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)aceticacid (15b)

Step 1.(S)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-3,4-dihydronaphthalen-2(1H)-one:(S)-2-(4-fluorophenyl)-3-methylbutanoic acid 10a (1.05 g, 5.38 mmol;prepared as describe in Crameri, Y. et al. Tetrahedron: Asymmetry 1997,8: 3617-3623) was dissolved in benzene (18 mL, 0.3M) and thionylchloride (0.785 mL, 10.7 mmol) was added by syringe. The reaction wasthen heated to a gentle reflux under a blanket of nitrogen for fourhours. The reaction was concentrated under reduced pressure and analiquot was removed in order to confirm conversion to the acyl chlorideby ¹H NMR. The acyl chloride was dissolved in dichloromethane (150 mL,0.04M) and the resulting solution was cooled with an ice bath. Thereaction solvent was saturated with d₄-ethylene gas (ISOTEC, 98% D) for30 minutes. Next, aluminum trichloride (2.15 g, 16.1 mmol) was added asa single portion to the reaction and sparging was continued for anadditional 30 minutes. The reaction was poured into ice-cold HCl (100mL, 1M) and stirred for 10 minutes. The aqueous phase was extracted withdichloromethane (3×50 mL). The combined organics were dried over sodiumsulfate, filtered, and concentrated to give a yellow oil. Purificationwith an ISCO flash chromatography instrument using heptanes/ethylacetate as the eluent (gradient: 0-100%) afforded 12b as a colorless oil(570 mg, 2.97 mmol, 58% yield). ¹H NMR (400 MHz, CDCl₃): δ 7.01 (m, 1H),6.91 (m, 2H), 3.05 (d, J=8 Hz, 1H), 2.20 (m, 1H), 1.00 (d, J=6.4 Hz,3H), 0.81 (d, J=6.4 Hz, 1H).

Step 2.2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)aceticacid (15b): A solution of diisopropylamine (0.906 mL, 6.5 mmol) intoluene (13 mL) was cooled with a dry ice acetone bath to −78° C. Nextwas added a 1.5M n-butyllithium solution (4.33 mL, 6.5 mmol) by syringeand the resulting solution of LDA was stirred for 10 minutes at −78° C.followed by warming to 0° C. for 30 minutes. The solution was thencooled to −78° C. again and tert-butylacetate (1.05 mL, 7.80 mmol) wasadded as a neat oil. The reaction was stirred for an additional 30minutes to afford an approximately 0.5 M solution of tert-butylacetatelithium enolate.

In a separate flask ketone 12b (450 mg, 2.14 mmol) was dissolved intoluene (12 mL, 0.18M) and cooled to −78° C. Then the previouslyprepared 0.5M enolate solution (9.42 mL, 4.71 mmol) was added to thesolution of 12b over 30 minutes by syringe pump. After 1 hour, thereaction was transferred to a cryocool chiller set to −20° C. andstirred under a balloon of nitrogen for 12 hours. The reaction waspoured into an ice-cold 1M HCl (100 mL) solution and the mixture wasextracted with ethyl acetate. The combined organic solutions wereconcentrated to give tert-butyl2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetate(14b) as a colorless oil (0.698 g, 2.14 mmol).

Intermediate 14b (0.698 g, 2.14 mmol) was dissolved in formic acid (1mL) and stirred at ambient temperature for 4 hours. Water (0.75 mL) wasadded and the reaction heated to 75° C. for 10 minutes. The reaction wascooled and concentrated with a lyopholizer to give intermediate 15b as awhite solid (513 mg, 1.90 mmol, 90% yield for the two steps). MS(M−H):269.16.

Example 2 Preparation ofN-(3-(1H-benzo[d]imidazol-2-yl)propyl)-N-methyl-2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetamide[35b (Formula IIa, whereinY⁸═Y⁹═Y^(5a/b)═Y^(3a/b)═Y^(2a/b)═Y^(6a/b)═Y^(7a/b)═H,Y^(1a/b)═Y^(4a/b)=D and R^(a)═R^(b)═R¹═CH₃)]

Step 1.N-(3-(1H-benzo[d]imidazol-2-yl)propyl)-N-methyl-2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetamide(17b): Intermediate 15b (84 mg, 0.310 mmol.),3-(1H-benzo[d]imidazol-2-yl)-N-methylpropan-1-amine 16e (148 mg, 0.745mmol; prepared as described in Lee, H. K. et al. Bioorganic MedicinalChemistry Letters 2008, 18: 4424-4427) and 1-hydroxybenzotriazolehydrate (HOBT) (78 mg, 0.508 mmol) were dissolved in 2-methyltetrahydrofuran (2.71 mL). In a separate flask was dissolvedN-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDCI) (156mg, 0.812 mmol) in water (2.71 mL). The two solutions were combined andstirred under a nitrogen atmosphere for 12 hours. The reaction wasquenched with aqueous ammonium chloride solution and extracted withethyl acetate. After drying over sodium sulfate, filtration andconcentration, the crude material was purified by an ISCO flashchromatography instrument (elution gradient: 0-100% ethylacetate-heptanes) to yield intermediate 17b as a colorless oil (100 mg,0.227 mmol, 73% yield). MS [M+H]: 442.3.

Step 2.1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)propyl)(methyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol(35b): A solution of sodium bis(2-methoxyethoxy)aluminum hydride(Red-Al) in toluene (0.125 mL, 0.408 mmol) was diluted with additionaltoluene (0.5 mL) and cooled to 0° C. with an ice bath. A toluenesolution (1.0 mL) of 17b (60 mg, 0.136 mmol) was introduced by cannula.After 30 minutes the reaction was allowed to warm to ambient temperatureand then heated to 40° C. with an oil bath. The reaction was thenstirred under a nitrogen atmosphere at this temperature for 12 hours. Itwas then cooled, diluted with toluene, and poured into ice cold aqueoussodium hydroxide (1N). The suspension was allowed to warm to ambienttemperature. The biphasic mixture was partitioned between water andtoluene. The combined organics were dried over sodium sulfate, filteredand concentrated to afford a yellow oil. The crude material was purifiedwith an ISCO flash chromatography instrument, using a 0-20%methanol/dichloromethane/5% ammonia elution gradient, to yield 35b as acolorless oil (40 mg, 0.094 mmol, 69% yield). MS (M+H): 428.4.

Example 3 Preparation ofN-(3-(1H-benzo[d]imidazol-2-yl)propyl)-N-methyl-2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetamide[35c (Formula IIa, wherein Y⁸═Y⁹═Y^(5a/b)═Y^(3a/b)═H,Y^(1a/b)═Y^(4a/b)═Y^(2a/b)═Y^(6a/b)═Y^(7a/b)=D, R¹═CD₃, andR^(a)═R^(b)═CH₃)]

Step 1.N-(3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)-2-((1S,2S)-3,3,4,4-tetradeutero-6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)-N-(trideuteromethyl)acetamide(17c): 17c was prepared using the procedure for 17b above (Example 2,Step 1) from the union of 15b (162 mg, 0.597 mmol) and amine 16a (130mg, 0.657 mmol; prepared as described in Example 8 below) to provide 17cas a colorless oil (140 mg, 0.311 mmol, 52% yield). MS (M+H): 451.4.

Step 2.(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)(trideuteromethyl)amino)-ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol(35c): 35c was prepared, using the procedure for 35b above (Example 2,Step 2), from the treatment of 17c (140 mg, 0.311 mmol) with Red-Alsolution (0.285 mL, 0.933 mmol) to give 35c as a colorless oil (95 mg,0.218 mmol, 70% yield). MS (M+H): 437.4.

Example 4 Synthesis of(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)propyl)(methyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl2-methoxyacetate (Compound 500)

(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)propyl)methyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl2-methoxyacetate(Compound 500): 35b (20 mg, 0.046 mmol) was dissolved in toluene (1 mL).Potassium carbonate (26 mg, 0.184 mmol) and methoxyacetyl chloride(0.015 mL, 0.150 mmol) were added and stirred under a nitrogenatmosphere. Upon completion, the reaction was diluted with ethyl acetateand washed with aqueous sodium hydroxide (1N). The combined organicsolutions were dried over sodium sulfate, filtered and concentrated togive an oil which was purified on silica gel to give Compound 500 as acolorless oil (16 mg, 0.032 mmol, 70% yield). ¹H NMR (400 MHz, CDCl₃) δ:7.44 (m, 2H), 7.20 (m, 2H), 6.91 (m, 1H), 6.86 (m, 1H), 6.72 (dd, J=9.6,2.8 Hz, 1H), 4.04 (d, J=3.7 Hz, 2H), 3.46 (s, 3H), 3.32 (brs, 1H), 3.10(m, 2H), 2.89 (m, 1H), 2.70 (m, 2H), 2.43 (s, 3H), 2.13-1.91 (m, 4H),1.05 (d, J=7.2 Hz, 3H), 0.42 (d, J=7.2 Hz, 3H). MS(M+H): 500.4.

Example 5 Synthesis of(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)(trideuteroomethyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl2-methoxyacetate (Compound 703a)

(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)(trideuteroomethyl)-amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl2-methoxyacetate (Compound 703a): Compound 703a was prepared using themethod described in Example 4 from 35c (21 mg, 0.048 mmol). Compound703a was obtained as a colorless oil (17 mg, 0.033 mmol, 69.6% yield).¹H NMR (400 MHz, CDCl₃): δ 7.50 (m, 2H), 7.20 (m, 2H), 6.93 (m, 1H),6.81 (m, 1H), 6.76 (m, 1H), 4.04 (q, J=14 Hz, 2H), 3.89 (s, 1H), 3.46(s, 3H), 3.29 (brs, 1H), 2.94 (m, 1H), 2.70 (m, 1H), 2.35 (m, 1H), 2.0(m, 1H), 1.60 (m, 1H), 1.05 (d, J=8.0 Hz, 3H), 0.42 (d, J=8.0 Hz, 3H).MS (M+H): 509.4.

Example 6 Synthesis of(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)propyl)(methyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ylcyclopropanecarboxylate (Compound 704a)

(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)propyl)(methyl)amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ylcyclopropanecarboxylate (Compound 704a: 35b (13 mg, 0.046 mmol) wasdissolved in toluene (1 mL). Potassium carbonate (26 mg, 0.184 mmol) andcyclopropanecarbonyl chloride (0.015 mL, 0.164 mmol) were added and thereaction was stirred under a nitrogen atmosphere. After 2 h the mixturewas concentrated nearly to dryness and the residue was re-dissolved in a5% acetic acid/methanol solution (1 mL). The mixture was allowed to stirat ambient temperature until the reaction was deemed complete by LCMS.The mixture was diluted with ethyl acetate and washed with aqueoussodium hydroxide (1N). The organic phase was dried over sodium sulfate,filtered and concentrated to give an oil which was purified on silicagel to afford Compound 704a as a colorless oil (16 mg, 0.032 mmol, 70%yield). ¹H NMR (400 MHz, CDCl₃): δ 7.44 (m, 2H), 7.18 (m, 2H), 6.93 (m,1H), 6.77 (m, 2H), 4.04 (q, J=14 Hz, 2H), 3.31 (brs, 1H), 3.09 (m, 2H),2.85 (m, 1H), 2.65 (m, 3H), 2.38 (brs, 4H), 2.08 (m, 3H), 1.93 (m, 1H),1.62 (m, 2H), 1.04 (d, J=8.0 Hz, 3H), 0.85 (m, 4H), 0.42 (d, J=8.0 Hz,3H). MS (M+H): 496.4.

Example 7 Synthesis of(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeutoropropyl)(trideuteromethyl)-amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ylcyclopropanecarboxylate (Compound 707a

(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)(trideuteromethyl)-amino)ethyl)-3,3,4,4-tetradeutero-6fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ylcyclopropanecarboxylate (Compound 707a): Compound 707a was preparedaccording to the method described in Example 6 from 35c (26 mg, 0.060mmol) to yield Compound 707a as a colorless oil (17 mg, 0.034 mmol, 56%yield). ¹H NMR (400 MHz, CDCl₃): δ 7.45 (m, 2H), 7.18 (m, 2H), 6.93 (m,1H), 6.77 (m, 2H), 4.04 (q, J=14 Hz, 2H), 3.49 (s, 1H), 3.29 (brs, 1H),3.00 (m, 1H), 2.73 (m, 1H), 2.35 (m, 1H), 2.04 (m, 2H), 1.62 (m, 1H),1.04 (d, J=8.0 Hz, 3H), 0.89 (m, 4H), 0.42 (d, J=8.0 Hz, 3H). MS (M+H)505.4.

Example 8 Synthesis of(1S,2S)-2-(2-((3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeuteropropyl)(trideuteromethyl)-amino)ethyl)-3,3,4,4-tetradeutero-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ylcyclopropanecarboxylate (16a)

Step 1. 4-(trideuteromethyl)amino)-2,2,3,3,4,4-butanoic acid (20):3,3,4,4,5,5-hexadeutero-1-(trideuteromethyl)pyrrolidin-2-one 19a (2.0 g,18.5 mmol, 98% atom D, CDN Isotopes) was dissolved in deuterium chloride(3 mL, 99% atom D) and heated to a gentle reflux for 12 hours. Thereaction was cooled and concentrated to give2,2,3,3,4,4-hexadeutero-4-((trideuteromethyl)amino)butanoic acid 20 as atacky white semi-solid, which was used in the next step without furtherpurification.

Step 2.4-(benzyloxy)carbonyl)(trideuteromethyl)amino)-2,2,3,3,4,4-hexadeuterobutanoicacid (21): 20 was dissolved in a 4:1 mixture of dioxane and water (100mL) and cooled to 0° C. Potassium carbonate was added (5.62 g, 40.66)followed by benzyl chloroformate (2.87 mL, 20.3 mmol). The reaction wasallowed to warm to ambient temperature over 12 hours. The mixture wasthen concentrated, and the residue remaining after concentration wasre-dissolved in ethyl acetate. The biphasic mixture was separated andthe organic phase was washed successively with aqueous saturated sodiumbicarbonate solution and brine. The combined organic solutions weredried over sodium sulfate, filtered, and concentrated to give an orangeoil which was purified on ISCO flash chromatography instrument (elutiongradient: 0-100% ethyl acetate/heptanes) to yield intermediate 21 as acolorless oil (3.20 g, 12.3 mmol, 66% yield over 2 steps). MS (M+H):259.2.

Step 3.Benzyl(4-((2-aminophenyl)amino)-1,1,2,2,3,3-hexadeutero-4-oxobutyl)(trideuteromethyl)carbamate(24): 21 (0.5 g, 1.92 mmol) was dissolved in tetrahydrofuran (8 mL) andcarbonyldiimidazole (0.24 g, 2.31 mmol) and o-phenylenediamine (0.46 g,4.22 mmol) were added. The reaction was allowed to warm to ambienttemperature over 12 hours. The mixture was concentrated and the residueremaining after concentration re-dissolved in ethyl acetate. Thebiphasic mixture was separated and the organic phase was washedsuccessively with aqueous saturated ammonium chloride solution andbrine. The combined organic solutions were dried over sodium sulfate,filtered, and concentrated to give a yellow oil which was purified onISCO flash chromatography instrument (elution gradient: 0-100% ethylacetate/heptanes) to yield intermediate 24 as a colorless oil (220 mg,0.64 mmol, 33% yield). MS (M+H): 351.2.

Step 4.benzyl(3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexachloropropyl)(trichloromethyl)carbamate(25): 24 (296 mg, 0.85 mmol) was dissolved in toluene (85 mL) andp-toluenesulfonic acid (17 mg, 0.09 mmol) was added. The mixture washeated to a gentle reflux for 12 hours, cooled, concentrated anddirectly transferred to an ISCO column. Purification (elution gradient:0-100% ethyl acetate/heptanes) yielded intermediate 25 as a colorlessoil (239 mg, 0.72 mmol, 85% yield). MS (M+H): 333.2.

Step 5.3-(1H-benzo[d]imidazol-2-yl)-1,1,2,2,3,3-hexadeutero-N-(trideuteromethyl)propan-1-amine(16a): 25 (375 mg, 1.13 mmol) was dissolved in methanol (12 mL) and 10%by wt. palladium on carbon (120 mg) was added as a single portion. Thereaction was placed under a balloon of hydrogen and allowed to stir for12 h. The reaction mixture was concentrated and the residue remainingafter concentration was re-dissolved in ethyl acetate and filteredthrough Celite to give intermediate 16a as a white solid (187 mg, 0.944mmol, 84% yield). MS (M+H): 199.3.

Example 9 Investigation of CYP3A4 Mechanism-Based Inhibition byMibefradil and D-Mibefradils Using Testosterone as the CYP3A4 MarkerSubstrate

Human liver microsomes (final concentration 0.13 mg/mL) werepre-incubated with test compounds mibefradil, 500, and 703a for 0 min, 1min, and 3 min each. The concentrations of the test compounds were: 0.2,0.3, 0.4, 0.5, 0.6, 0.8, 1, 2, 3, 4, and 5 μM. After the pre-incubation,the samples were diluted 1:10 into buffer containing 200 μM testosteroneand 2 mM NADPH and these mixture were incubated for another 10 minutes.Incubations were stopped with acetonitrile containing an internalstandard. Samples were then centrifuged at 3000 rpm for 10 minutes andthe supernatant were analyzed for the formation of 6-β-hydroxytestosterone by LC-MS/MS.

The inactivation rate constants (k_(obs)) were determined from theinitial slopes of plots of LN (CYP activity) remaining versuspreincubation time. The k_(inact) and K₁ values were estimated fromplots of k_(obs) versus inhibitor concentration by non-linear regressionanalysis using GraphPad Prism v5.01, according to the equation shownbelow:

K _(obs) =k _(inact) *X/(K _(i) +X)

where X is the inhibitor concentration.

Example 10 Evaluation of Metabolic Stability

Microsomal Assay: Human liver microsomes (20 mg/mL) were obtained fromXenotech, LLC (Lenexa, Kans.). β-nicotinamide adenine dinucleotidephosphate, reduced form (NADPH), magnesium chloride (MgCl₂), anddimethyl sulfoxide (DMSO) were purchased from Sigma-Aldrich.

Determination of Metabolic Stability: 7.5 mM stock solutions of testcompounds were prepared in DMSO. The 7.5 mM stock solutions were dilutedto 12.5-50 μM in acetonitrile (ACN). The 20 mg/mL human liver microsomeswere diluted to 0.625 mg/mL in 0.1 M potassium phosphate buffer, pH 7.4,containing 3 mM MgCl₂. The diluted microsomes were added to wells of a96-well deep-well polypropylene plate in triplicate. A 10 μL aliquot ofthe 12.5-50 μM test compound was added to the microsomes and the mixturewas pre-warmed for 10 minutes. Reactions were initiated by addition ofpre-warmed NADPH solution. The final reaction volume was 0.5 mL andcontained 0.5 mg/mL human liver microsomes, 0.25-1.0 μM test compound,and 2 mM NADPH in 0.1 M potassium phosphate buffer, pH 7.4, and 3 mMMgCl₂. The reaction mixtures were incubated at 37° C., and 50 μLaliquots were removed at 0, 5, 10, 20, and 30 minutes and added toshallow-well 96-well plates which contained 50 μL of ice-cold ACN withinternal standard to stop the reactions. The plates were stored at 4° C.for 20 minutes after which 100 μL of water was added to the wells of theplate before centrifugation to pellet precipitated proteins.Supernatants were transferred to another 96-well plate and analyzed foramounts of parent remaining by LC-MS/MS using an Applied Bio-systems API4000 mass spectrometer. The same procedure was followed for thenon-deuterated counterpart of the compound of Formula B, Formula A,Formula I, Formula B-I, or Formula C and the positive control,7-ethoxycoumarin (1.0 μM). Testing was done in triplicate.

Data analysis: The in vitro t_(1/2)s for test compounds were calculatedfrom the slopes of the linear regression of % parent remaining (ln) vsincubation time relationship.

in vitro t _(1/2)=0.693/k

-   -   k=−[slope of linear regression of % parent remaining(ln) vs        incubation time]

Data analysis was performed using Microsoft Excel Software.

The results of the mechanism-based inhibition (MBI) study in human livermicrosomes (HLM) are shown in FIG. 1 and in Table 7 below. As both FIG.1 and the table show, CYP3A4 mechanism-based inhibition of compound 500and compound 703a is markedly reduced relative to mibefradil.

TABLE 7 Results of In Vitro MBI Studies in HLM Compound K_(i) (μM)k_(inact) (μM) Mibefradil 0.66 ± 0.18^(a) 0.37 ± 0.11^(a) 500 Notcalculable Not calculable 703a Not calculable Not calculable ^(a)average± SD, N = 3 experiments. Literature values for Mibefradil according toPreuksaritanont, T. et al., Br. J. Clin. Pharmacol. 1999, 47, 291-298:K_(I) = 2.3 μM, k_(inact) = 0.4 min^(−1,) Partition ratio = 1.7

The results of the human liver microsome study are shown in the tablesbelow.

TABLE 8a Results of In Vitro HLM Studies for deuterated-Mibefradilt_(1/2) (min) Compound Experiment 1 Experiment 2 Ave Mibefradil 8.498.55 8.52 500 4.61 4.98 4.79 703a 7.17 7.72 7.45

TABLE 8b Results of In Vitro HLM Studies for deuterated-NNC 55-0396¹t_(1/2)(min) Compound Experiment 1 Experiment 2 Ave NNC 55-0396 6.586.55 6.56 704a 6.16 6.60 6.38 707a 7.27 7.03 7.15 ¹The structure of NNC55-0396 is:

The results of the human liver microsome study, as shown in Table 8aabove, reveal that the half life (t_(1/2)) of compound 500 isapproximately 44% shorter than that of mibefradil. This result furthersupports the showing above of reduction/removal of mechanism basedinhibition for compound 500 relative to mibefradil.

Without further description, it is believed that one of ordinary skillin the art can, using the preceding description and the illustrativeexamples, make and utilize the compounds of the present invention andpractice the claimed methods. It should be understood that the foregoingdiscussion and examples merely present a detailed description of certainpreferred embodiments. It will be apparent to those of ordinary skill inthe art that various modifications and equivalents can be made withoutdeparting from the spirit and scope of the invention.

1. A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein: R^(a), R^(b) andR^(c) are each independently selected from —CH₃, —CDH₂, —CD₂H, and —CD₃;Y^(1a) and Y^(1b) are each independently selected from hydrogen,deuterium, and fluorine; Y^(2a) and Y^(2b) are each independentlyselected from hydrogen and deuterium; Y^(3a) and Y^(3b) are eachindependently selected from hydrogen and deuterium; Y^(4a) and Y^(4b)are each independently selected from hydrogen and deuterium; and R¹ isselected from —CH₃, —CDH₂, —CD₂H, and —CD₃; provided that when each ofY^(1a), Y^(1b), Y^(2a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), and Y^(4b) ishydrogen, R¹ comprises at least one deuterium.
 2. The compound of claim1, wherein: R^(a), R^(b) and R^(c) are each —CH₃; Y^(1a) and Y^(1b) arethe same, or Y^(1a) is fluorine and Y^(1b) is selected from hydrogen anddeuterium; Y^(2a) and Y^(2b) are the same; and R¹ is selected from —CH₃and —CD₃.
 3. The compound of claim 2, wherein each Y¹ is deuterium. 4.The compound of claim 2, wherein each Y¹ is fluorine.
 5. The compound ofclaim 2, wherein Y^(1a) is fluorine and Y^(1b) is selected from hydrogenand deuterium.
 6. The compound of claim 2, wherein each Y¹ is hydrogen.7. The compound of any one of claims 3-6, wherein R¹ is —CD₃.
 8. Thecompound of any one of claims 3-6, wherein R¹ is —CH₃.
 9. The compoundof any one of claims 3-8, wherein each Y² is hydrogen.
 10. The compoundof any one of claims 3-8, wherein each Y² is deuterium.
 11. The compoundof any one of claims 3-10, wherein each Y³ is hydrogen.
 12. The compoundof any one of claims 3-10, wherein each Y³ is deuterium.
 13. Thecompound of claim 2, wherein R¹ is —CD₃; and each Y² is hydrogen. 14.The compound of claim 2, wherein R¹ is —CD₃; and each Y² is deuterium.15. The compound of any one of claims 1-14, wherein any atom notdesignated as deuterium is present at its natural isotopic abundance.16. The compound of claim 2 wherein each Y¹ is the same, each Y³ is thesame, each Y⁴ is hydrogen, and the compound is selected from any one ofthe compounds in the table below, or a pharmaceutically acceptable saltthereof, wherein any atom not designated as deuterium is present at itsnatural isotopic abundance: Cmpd # Each Y¹ R¹ Each Y² Each Y³ 100 D CH₃H H 101 D CD₃ H H 102 D CH₃ D H 103 D CD₃ D H 104 F CH₃ H H 105 F CD₃ HH 106 F CH₃ D H 107 F CD₃ D H 108 H CD₃ H H 109 H CH₃ D H 110 H CD₃ D H111 D CH₃ H D 112 D CD₃ H D 113 D CH₃ D D 114 D CD₃ D D 115 F CH₃ H D116 F CD₃ H D 117 F CH₃ D D 118 F CD₃ D D 119 H CD₃ H D 120 H CH₃ D D121 H CD₃ D D


17. The compound of claim 2, wherein Y^(1a) is fluorine, each Y³ is thesame, each Y⁴ is hydrogen, and the compound is selected from any one ofthe compounds in the table below, or a pharmaceutically acceptable saltthereof, wherein any atom not designated as deuterium is present at itsnatural isotopic abundance: Cmpd # Y^(1b) R¹ Each Y² Each Y³ 200 D CH₃ HH 201 D CD₃ H H 202 D CH₃ D H 203 D CD₃ D H 204 H CH₃ H H 205 H CD₃ H H206 H CH₃ D H 207 H CD₃ D H 208 D CH₃ H D 209 D CD₃ H D 210 D CH₃ D D211 D CD₃ D D 212 H CH₃ H D 213 H CD₃ H D 214 H CH₃ D D 215 H CD₃ D D


18. The compound of claim 2, wherein each Y⁴ is deuterium; each Y¹ isthe same; and each Y³ is the same, and the compound is selected from anyone of the compounds in the table below, or a pharmaceuticallyacceptable salt thereof, wherein any atom not designated as deuterium ispresent at its natural isotopic abundance: Cmpd # Each Y¹ R¹ Each Y²Each Y³ 500 D CH₃ H H 501 D CD₃ H H 502 D CH₃ D H 503 D CD₃ D H 504 FCH₃ H H 505 F CD₃ H H 506 F CH₃ D H 507 F CD₃ D H 508 H CD₃ H H 509 HCH₃ D H 510 H CD₃ D H 511 D CH₃ H D 512 D CD₃ H D 513 D CH₃ D D 514 DCD₃ D D 515 F CH₃ H D 516 F CD₃ H D 517 F CH₃ D D 518 F CD₃ D D 519 HCD₃ H D 520 H CH₃ D D 521 H CD₃ D D


19. A pyrogen free pharmaceutical composition comprising a compound ofclaim 1 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.
 20. The composition of claim 19,additionally comprising a second therapeutic agent selected from a betablocker, an aldose reductase inhibitor, a NSAIDs, a 5HT_(1D) agonist, adopamine D₂ receptor antagonist, a secale alkaloid, a second calciumchannel blocker and a neurokinin antagonist.
 21. A method of treating adisease or condition selected from angina pectoris, ischemia,arrhythmias, congestive heart failure, high blood pressure, cardiacinsufficiency, pain, visceral pain and diabetic complications in asubject comprising the step of administering to the subject in needthereof a composition of claim
 19. 22. The method of claim 21, whereinthe disease or condition is selected from hypertension and anginapectoris.
 23. The method of claim 21, wherein the disease or conditionis congestive heart failure.
 24. The method of claim 21, wherein thedisease or condition is selected from arrhythmias, hypertension andangina pectoris, the method comprising the additional step ofco-administering to the subject in need thereof a beta blocker.
 25. Acompound of Formula A

or a pharmaceutically acceptable salt thereof, wherein: R^(a), R^(b) andR^(c) are each independently selected from —CH₃, —CDH₂, —CD₂H, and —CD₃;Y^(1a) and Y^(1b) are each independently selected from hydrogen,deuterium and fluorine; Y^(2a) and Y^(2b) are each independentlyselected from hydrogen and deuterium; Y^(3a) and Y^(3b) are eachindependently selected from hydrogen and deuterium; Y^(4a) and Y^(4b)are each independently selected from hydrogen and deuterium; Y^(5a) andY^(5b) are each independently selected from hydrogen and deuterium;Y^(6a) and Y^(6b) are each independently selected from hydrogen anddeuterium; Y^(7a) and Y^(7b) are each independently selected fromhydrogen and deuterium; Y⁸ is selected from hydrogen and deuterium; Y⁹is selected from hydrogen and deuterium; and R¹ is selected from —CH₃,—CDH₂, —CD₂H, and —CD₃; provided that when each of Y^(1a), Y^(1b),Y^(1a), Y^(2b), Y^(3a), Y^(3b), Y^(4a), Y^(4b), Y^(5a), Y^(5b), Y^(6a),Y^(6b), Y^(7a), Y^(7b), Y⁸ and Y⁹ is hydrogen, R¹ comprises at least onedeuterium.
 26. A compound of claim 25 wherein R^(a), R^(b) and R^(c) areeach —CH₃; each Y⁴ is deuterium; each Y¹ is the same; each Y² is thesame; each Y³ is the same; each Y⁵ is hydrogen; each Y⁶ is deuterium;each Y⁷ is deuterium; each Y⁸ is hydrogen; each Y⁹ is hydrogen, and thecompound is selected from any one of the compounds in the table below,or a pharmaceutically acceptable salt thereof, wherein any atom notdesignated as deuterium is present at its natural isotopic abundance:Cmpd # Each Y¹ R¹ Each Y² Each Y³ 600 D CH₃ H H 601 D CD₃ H H 602 D CH₃D H 603 D CD₃ D H 604 F CH₃ H H 605 F CD₃ H H 606 F CH₃ D H 607 F CD₃ DH 608 H CD₃ H H 609 H CH₃ D H 610 H CD₃ D H 611 D CH₃ H D 612 D CD₃ H D613 D CH₃ D D 614 D CD₃ D D 615 F CH₃ H D 616 F CD₃ H D 617 F CH₃ D D618 F CD₃ D D 619 H CD₃ H D 620 H CH₃ D D 621 H CD₃ D D


27. A pyrogen free pharmaceutical composition comprising a compound ofclaim 25 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.
 28. A method of treating a diseaseor condition selected from angina pectoris, ischemia, arrhythmias,congestive heart failure, high blood pressure, cardiac insufficiency,pain, visceral pain and diabetic complications in a subject comprisingthe step of administering to the subject in need thereof a compositionof claim
 27. 29. A compound of Formula C

or a pharmaceutically acceptable salt thereof, wherein R^(d) and R^(e)are each independently hydrogen or deuterium; or R^(d) and R^(e) takentogether with the carbon to which they are connected form a 3-memberedcarbocyclic ring that is optionally substituted with deuterium; providedthat if R^(d) and R^(c) are each independently hydrogen or deuterium,then R^(f) is OR^(c) wherein R^(c) is selected from —CH₃ and —CD₃; andprovided that if R^(d) and R^(e) taken together with the carbon to whichthey are connected form a 3-membered carbocyclic ring, then R^(f) ishydrogen or deuterium; Y^(3a) and Y^(3b) are each independently selectedfrom hydrogen and deuterium; Y^(5a) and Y^(5b) are each independentlyselected from hydrogen and deuterium; Y⁸ is selected from hydrogen anddeuterium; Y⁹ is selected from hydrogen and deuterium; R¹ is selectedfrom —CH₃ and —CD₃; and each of Y^(2a), Y^(2b), Y^(6a), Y^(6b), Y^(7a)and Y^(7b) is the same and is either hydrogen or deuterium.
 30. Thecompound of Formula C, wherein the compound is selected from any one ofthe compounds set forth in the table below, or a pharmaceuticallyacceptable salt thereof, wherein Y⁸, Y⁹ are each hydrogen; R^(a) andR^(b) are each —CH₃, and each of Y^(3a), Y^(3b), Y^(5a), and Y^(5b) ishydrogen, and wherein any atom not designated as deuterium is present atits natural isotopic abundance: Cmpd # R¹ Each of Y^(2a), Y^(2b),Y^(6a), Y^(6b), Y^(7a) and Y^(7b)

701a CH₃ D CH₂OCH₃ 702a CD₃ H CH₂OCH₃ 703a CD₃ D CH₂OCH₃


31. The compound of Formula C, wherein the compound is selected from anyone of the compounds set forth in the table below, or a pharmaceuticallyacceptable salt thereof, wherein Y⁸, Y⁹ are each hydrogen; R^(a) andR^(b) are each —CH₃, and each of Y^(3a), Y^(3b), Y^(5a), and Y^(5b) isdeuterium, and wherein any atom not designated as deuterium is presentat its natural isotopic abundance: Cmpd # R¹ Each of Y^(2a), Y^(2b),Y^(6a), Y^(6b), Y^(7a) and Y^(7b)

700b CH₃ H CH₂OCH₃ 701b CH₃ D CH₂OCH₃ 702b CD₃ H CH₂OCH₃ 703b CD₃ DCH₂OCH₃


32. A pyrogen free pharmaceutical composition comprising a compound ofclaim 29 or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable carrier.
 33. A method of treating a diseaseor condition selected from angina pectoris, ischemia, arrhythmias,congestive heart failure, high blood pressure, cardiac insufficiency,pain, visceral pain and diabetic complications in a subject comprisingthe step of administering to the subject in need thereof a compositionof claim 32.